A process for converting light to electricity at an efficiency of at least about fifty percent.
Commercially available prior art devices for converting light to electricity are relatively inefficient. These commercially available devices include photocells, which are characterized by the efficiency with which they can convert incident light energy to useful electrical energy. In general, such efficiency does not exceed about 23 percent. Thus, as is disclosed in U.S. Pat. No. 6,278,055, xe2x80x9c. . . photosensitive optoelectronic devices have been constructed of a number of inorganic semiconductors . . . Solar cells are characterized by the efficiency with which they can convert incident solar power to useful electric power. Devices utilizing crystalline or amorphous silicon dominate commercial applications and some have achieved efficiencies of 23% or greater. However, efficient crystalline-based devices, especially of large surface area, are difficult and expensive to produce due to the problems inherent in producing large crystals without significant efficiency-degrading defects.xe2x80x9d
It is an object of this invention to provide a process for converting light to electricity which is substantially more efficient and reliable than prior art processes.
In accordance with this invention, there is provided a process comprising the steps of: transmitting light at a first wavelength through a first optical layer, transmitting said light with said first wavelength through a photocell element and a second optical layer, converting said light with said first wavelength while it is within said second optical layer to light with a second wavelength, reflecting said light with a second wavelength from a mirror, transmitting said light with a second wavelength which has been internally reflected by said mirror through said photocell element and said second optical layer to said first optical layer, and internally reflecting said light with a second wavelength which has been internally reflected by said mirror through said photocell element from said first optical layer.